The present invention relates to disc brakes and more particularly to a front and rear disc brake system for a motorcycle.
Due to the short wheel bases and high centers of gravity associated with motorcycles, brake systems for motorcycles are uniquely designed to accomodate these considerations. More specifically, it is necessary to have significantly greater braking power on the front wheel than on the rear wheel. The rear brake is used more in slow speed stops and is also shielded from a cooling air flow and thus, although it does not need to have great power, it must be able to store or dissipate large amounts of heat.
High performance sport motorcycles typically utilize two front brake discs having an outside diameter between 10.50 and 12.50 inches and a thickness between 3/16 to 1/4 of an inch. The rear discs utilized in such a motorcycle are typically 8.50 to 10.50 inches in diameter and also have a thickness between 3/16 and 1/4 of an inch. A touring or more general use type of motorcycle will utilize a rear disc having a diameter between 10 and 12 inches and a thickness between 3/16 and 1/4 of an inch.
Discs of this type are manufactured from martensitic stainless steel or the more expensive stainless clad aluminum. The discs are stamped or blanked out of sheet stock and typically a disc having an 11.50 inch outer diameter and a 6 inch inner diameter requires a 12.25 inch square of 1/4 inch thick rolled material. When such a disc is stamped from the 12.25 inch square, there is approximately 75 square inches of waste material. Similarly, a disc having a 10 inch outer diameter and a 5 inch inner diameter wastes approximately 58 square inches of material when stamped from a 10.75 inch square. Therefore, the stamping of a dual front disc, single rear disc system, such as that discussed above, results in a material waste of approximately 208 square inches per brake system.
It is an object of the present invention to provide a motorcycle disc brake system that will allow for the stamping of a front and rear disc from a single sheet of material stock and thus, greatly reduce the amount of material waste typically associated with the stamping of brake discs.